Your mobile wallet is online. Online wallets are not safe like cold wallets which are offline.
My advise is that you should not hold more than the amount that you can afford to lose on mobile wallets. It is good to get yourself a cold wallet. If you can not buy a hardware wallet, you can go for wallet on airgapped device.
Or you can go for multisig wallet if you need a safe online wallet. If you have 2 or 3 phones, you can use it to setup a multisig wallet.
The wallets that I have used on mobile phone that I can recommend are Bluewallet, Electrum and Samourai. For multisig, use Electrum. Although, Bluewallet has 2-of-3 multisig which is called vault, but Electrum multisig is perfect as you can use it for up to 15 signers and also you will be able to use it for 2-of-2 multisig.